This invention relates to an improved soldering method which may be applicable to any circular member to be soldered rigidly, more particularly to a soldering method for soldering an inlet and an outlet pipe to a flat tube in the evaporator of a cooling system.
In a conventional method for soldering such a member to a tube, an aperture is formed on an outer surface of the pipe and, then, a member, such as aforementioned flat tube is inserted through the aperture and a solder is put therearound. Thereafter, such arrangement is subjected to heat which is enough to melt the solder usually in a vacuum furnace. At that time, the solder often goes out of the clearance between the flat tube and aperture and, moreover, the edge of the aperture is apt to deform because of the high temperature, resulting in poor sealing function and inaccurate configuration. Furthermore it is not easy to form the aperture on the outer surface of the pipe, because a die inserted into the pipe to form the aperture can not endure a long-time use, especially when the diameter of the pipe is small.